0.520grams octane burned in a bomb calorimeter with 1.20kg water at temp of 25.0⁰C. After the reaction, the temp raises to 33.2⁰C. If the calorimeter constant is 837J/⁰C, calculate the ΔH in kJ/mol of octane.
ΔH= -10,500kJ/mol
The combustion of 4.000grams of octane produces 128.6kJ. What is the ΔH in kJ/mol?
ΔH= -3665kJ/mol
N2(g) + 2O2(g) à 2NO2(g) ΔH=-436kJ
Sign on ΔH⁰?
Sign on ΔS⁰?
Sign on ΔG⁰? -, -, - low temps
Energy released when 5.00grams O2 burned?
34.1kJ
Energy released when 0.50moles N2 burned?
218kJ
2C2H6 + 7O2 à 4CO2 + 6H2O
ΔHf⁰H2O= -285.8kJ/mol
ΔHf⁰CO2= -393.3kJ/mol
ΔHcomb= -1942kJ/mol
Calculate ΔHf⁰C2H6 -673kJ/mol
ΔH⁰= -566.0kJ/mol and ΔS⁰= -173.6J/K for the reaction:
2CO(g) + O2(g) ó 2CO2(g).
Calculate ΔG⁰ -514.4kJ/mol
Is reaction thermodynamically favorable? yes
What drives this reaction? ΔH
At what temperature would the reaction not be spontaneous? 3260K and higher
2Br(g) à Br2(g)
ΔH? ΔS? ΔG? -,-,- low temps
NH4NO3 dissolves in water-temp decreases
ΔH? ΔS? ΔG? +,+,- high temps
H2O(l) à H2O(s)
ΔH? ΔS? ΔG? -,-,- low temps
E+ 2Cl2O(g) à 2Cl2(g) + O2(g)
ΔH? ΔS? ΔG? +,+,- high temps
E + 2FeS(s) + 3O2(g) à 2FeO(s) + 2SO2(g)
ΔH? ΔS? ΔG? +,-,+
KCl(s) à K+(aq) + Cl-(aq) temp increases
ΔH? ΔS? ΔG? -,+,-
Calculate B.P. when ΔH=46.6kJ/mol and ΔS=122J/mol•K
382K
Calculate ΔG at 400K when ΔG⁰ is -46.25kJ/mol when the pressure of the reactants are 5.0atm each and pressure of the product is 2.0atm for this reaction: H2 + F2 ó 2HF -52.3kJ/mol
What are the conditions of ΔG and K when reaction is thermodynamically favored? ΔG -, K>1
NH4+ à NH3 + H+ K=2.50 x 10-5
Predict the sign on ΔG⁰ ΔG +
Calculate ΔG⁰ ΔG = 26.2kJ/mol
In a different reaction,
ΔG⁰= -12.60 kJ/mol
K=? K=162
ΔHf⁰(kJ/mol) / S⁰(J/mol•K)HCOOH(l) / -410 / 130
HCOOH(g) / -363 / 251
Calculate the boiling point (°C) of formic acid (HCOOH)? 115°C
ΔH=5.5kJ/mol ΔS=-25.0J/mol•K
At what temperature conditions is the reaction spontaneous?
Never
CH3CO2HóH+ + CH3CO2- Ka=1.8 x 10-5
Calculate ΔG⁰ 27.1kJ/mol
What is the ΔG at 25.0⁰C for a solution in which the initial concentrations are:
[CH3CO2H] = 0.10M
[H+] = 2.0 x 10-8M
[CH3CO2-] = 0.010M -22.5kJ/mol
Which of the following processes exhibits an increase in entropy?
a)N2O4(g) à 2NO2(g)
b) CH3OH(g) à CH3OH(l)
c)H2O(g) à H2O(s)
d) H2O(s) à H2O(l) a and d
A substance at 3.0atm and -82.0˚C is warmed to -20.0˚C. Name that change.
Sublimation
A substance at 50.0atm and -11.0˚C has pressure reduced to 5.0atm. Name that change. Vaporization
Hydrogen and Iodine gas react together to formhydrogen iodide gas.
H2(g) + I2(g) ↔ 2HI(g)
The equilibrium constant for this reaction is 710 at 25 °C. If the current concentration of gases are [H2]=0.81M [I2]=0.44M [HI]=0.58M, what direction will the rxn shift to reach equilibrium? Shifts right
Specific heats: solid=2.03J/g˚C, liquid=4.18J/g°C, gas=2.00J/g˚C.
ΔHf=334J/g, ΔHv=2258J/g
Calculate the energy released when 26.0grams of water vapor at 145.0˚C condenses to water at 65.0˚C. 64.9kJ
What conditions would the reaction be thermodynamically favorable?
ΔH +, ΔS- Never
ΔH +, ΔS+ High temps
ΔH -, ΔS+ Always
ΔH -, ΔS- Low